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Why don't my construction assembly values show up in my simultation while they are clearly input into in my .idf

asked 2014-11-07 21:48:23 -0500

petherington's avatar

updated 2021-05-07 12:05:01 -0500

I am new to Open Studio. I have taken over the research at a University where the last research assistant was running simulations of a model built in Sketchup. He previously input the construction assemblies in Energy Plus. I have his .idf file, although I am using a completely different version of Open Studio, he was using legacy, but when I run a simulation there are no r-values for my walls/ceilings, etc... Help Anyone?

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answered 2014-11-08 09:26:26 -0500

OpenStudio does not store any of the energy modeling information in the SketchUp file itself, but rather uses SketchUp as a visualization tool. Modifications made to the energy model (including the energy model geometry) are stored in a separate file. The Legacy OpenStudio SketchUp plugin stored this model information in a .IDF file (the EnergyPlus input file format). The current OpenStudio SketchUp plugin uses .OSM files (the OpenStudio input file format). The plugin has its own save, save-as, open and open buttons in the toolbar. The OpenStudio SketchUp Plugin Documentation explains how to use the plugin.

If your predecessor was using the Legacy OpenStudio SketchUp plugin, he should have IDF files of his model. You can import IDFs into the new versions of OpenStudio via the ->IDF button in the OpenStudio SketchUp plugin toolbar. However, be aware that IDF import only brings in geometry, constructions, loads, thermal zones, and schedules. This means that if your predecessor put in HVAC systems, you will need to add those back into the model via the HVAC Tab of the OpenStudio Application.

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Yes, pardon me, I meant IDF file not IFC, slip of the type finger. I have imported the IDF file (legcy version) it seems to run a simulation but there are no material properties. The interior temperatures don't seem to be affected by the walls/ceiling at all. I am tempted to re-enter all of the material properties through Open Studio but I don't want to waste time that my predecessor spent building up the model.

I have since run through it again and it appears the material properties are present but I have to go into Open Studio and re-sssign them to the walls/windows, etc..

petherington's avatar petherington  ( 2014-11-12 04:10:16 -0500 )edit

answered 2014-11-08 10:13:34 -0500

Regarding the thermal properties of the constructions, EnergyPlus/OpenStudio doesn't display or use R-values or U-factors as inputs, these are calculated during the simulation from Material properties. See the question below for how to specify and view these.

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Asked: 2014-11-07 21:48:23 -0500

Seen: 510 times

Last updated: Nov 12 '14